Distributed Operating Systems and Client-Server Architecture
System
A number of factors, processes, and methods that interact with each other toward a common goal.
Operating System
A software package that controls, manages, and regulates the functions of elements to achieve an objective and is stored in secondary memory.
Distributed Operating System
A software package to manage and control the functions of the control elements (hardware, software) that make up a system, which is transparent to the user.
Advantages (Distributed vs. Centralized)
- Economy
- Speed
- Reliability
- Incremental Growth
Disadvantages
- Software (There is little)
- Networks (Saturation)
- Security
Client-Server Model
Produces a request for information to any of the computers that provide information. The latter, known as servers, respond to the client application server that produced it.
Client
The one who initiates a service request.
Server
Any computing resource dedicated to meeting customer requirements.
Elements of the Client-Server Architecture
- Presentation/Information Collection
- Processes
- Storage Information
Client-Server Applications
- Workstation: A computer workstation connected to a network, allowing you to access and manage a range of resources, which is emerging as a universal job.
- Server: A machine that provides a range of services such as databases, files, and communications.
Communications
In its two aspects:
- Network Infrastructure: Hardware and software components that ensure the physical connection and transfer of data between computers on the network.
- Communications Infrastructure: Hardware and software components that enable communication and management between clients and servers.
Architecture
It is a network of functional components that utilize different standards, conventions, rules, and processes. It can integrate a wide range of products and services so they can be used effectively within the organization.
Two-Layer Client/Server Application
Data and business logic are separated from the interface. This application is also called a thin client.
Client/Server Application
Given the separation of the data interface and business logic, this type of application is also known as a thick client or heavy client.
Three-Layer Application
The interface, business logic, data access, and data are separated.
Network Operating Systems
A software package that controls the execution of application programs and acts as an interface between the user and the hardware of a computer.
Primary Function of an Operating System
- Hardware Management: Refers to managing the resources of the machine in a more efficient way.
- Facilitate User Work: It allows communication with devices on the machine.
Hardware Features
- SISD (Single Instruction, Single Data) (Normal PC): All computers that have a single processor.
- SIMD (Single Instruction, Multiple Data) (SOR): Refers to computers connected to each other, each with its own processor, where each processor looks for the instruction and instructs the others to process in parallel.
- MISD (Multiple Instruction, Single Data): No known computer fits this classification.
- MIMD (Multiple Instruction, Multiple Data): These are groups of independent computers, each with its own program counter and data. All distributed systems are of this type.
Distributed Operating Systems (DOS)
These systems can distribute jobs, tasks, or processes among a set of processors. This set of processors may be on a different computer, and in this case, it is transparent to the user.
Features
- Placement of autonomous systems capable of communication and cooperation through hardware and software.
- Provide means for global resource sharing.
- Added Services: Global denomination, distributed file systems, load distribution facilities.
Role of DOS
Administer:
- Hardware Resources (CD, HD, DVD, memory, etc.) and software.
- Processes (messages).
- Users (Who is going to use it?).
Offers:
- Catering to a client. (A client is one who asks, not necessarily one who must be a user).
- Application of something. Petitions to solve the system.